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/* - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008-2009 Sun Microsystems, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
*
* Defines the JoinTable class which is the primary class
* used in the nested loops join implementation.
*/
#ifndef DRIZZLED_TABLE_REFERENCE_H
#define DRIZZLED_TABLE_REFERENCE_H
#include <drizzled/base.h>
#include <drizzled/definitions.h>
namespace drizzled
{
class StoredKey;
class Item;
struct table_reference_st
{
table_reference_st() :
key_err(false),
key_parts(0),
key_length(0),
key(0),
key_buff(NULL),
key_buff2(NULL),
key_copy(NULL),
items(NULL),
cond_guards(NULL),
null_ref_key(NULL),
disable_cache(false)
{ }
bool key_err;
uint32_t key_parts; /**< num of key parts */
uint32_t key_length; /**< length of key_buff */
int32_t key; /**< key no (index) */
unsigned char *key_buff; /**< value to look for with key */
unsigned char *key_buff2; /**< key_buff+key_length */
StoredKey **key_copy; /**< No idea what this does... */
Item **items; /**< val()'s for each keypart */
/**
Array of pointers to trigger variables. Some/all of the pointers may be
NULL. The ref access can be used iff
for each used key part i, (!cond_guards[i] || *cond_guards[i])
This array is used by subquery code. The subquery code may inject
triggered conditions, i.e. conditions that can be 'switched off'. A ref
access created from such condition is not valid when at least one of the
underlying conditions is switched off (see subquery code for more details)
*/
bool **cond_guards;
/**
(null_rejecting & (1<<i)) means the condition is '=' and no matching
rows will be produced if items[i] IS NULL (see add_not_null_conds())
*/
key_part_map null_rejecting;
table_map depend_map; /**< Table depends on these tables. */
/** null byte position in the key_buf. Used for REF_OR_NULL optimization */
unsigned char *null_ref_key;
/**
true <=> disable the "cache" as doing lookup with the same key value may
produce different results (because of Index Condition Pushdown)
*/
bool disable_cache;
};
} /* namespace drizzled */
#endif /* DRIZZLED_TABLE_REFERENCE_H */
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